Sample receiving projectile for side wall core sampler



SAMPLE RECEIVING PROJECTILE FOR SIDE WALL CORE SAMPLER Filed Jan. 17,1956 [Once/7 1 eons INVENTOR.

SAMPLE RECEIVING PROJECTILE FOR-SIDE WALL CORE SAMPLER Vincent DominickLeone, Beaumont, Tex.

Application January 17, 1956, Serial No. 559,746

1 Claim. (Cl. 2551.4)

The invention relates to a sample receiving projectile for use inconjunction with a side wall core sampler of the type used to takesamples of earth formations from the side walls of well bores, and itconcerns more particularly a projectile for the purpose described havingan inner lining comprising a split sleeve adapted to receive the sampleas it is introduced into the projectile, the sleeve being made of springsteel and being capable of being expanded, due to its inherentresilience, upon removing the sleeve from the projectile with the samplecontained therein, whereby the sleeve is disengaged from the sample andthe sample may be recovered in one intact, unaltered piece.

There is a need in the oil industry for means for obtaining intactsamples representative of earth formations at different elevations belowthe surface. Such samples, which are commonly referred to as cores, andwhich may have structures ranging from those which are relativelyPatented Dec. 25,1956

fi we number of such designs now exist. One of the factors which mayaffect the design of the projectile isthe hardness of the formation fromwhich a core is desired.

When the sample receiving projectile, with the core contained therein,is recovered at the surface, the removal of the core sample therefrom isalways ditficult. This difliculty is due in part to the fact that, whenthe projectile strikes the side wall of the well bore, a compressionwave is set up in front of the projectile, thereby packing the core intothe projectile under compression.

Another factor affecting the manner in which the core money must bespent to obtain the sample, means for removing the sample from theprojectile in one intact, unaltered piece will'be of substantial benefitto the oil industry. If such samples are recovered in one intact,unaltered piece, core analysis tests may be obtained which will indicateaccurately the productive characteristics and capacity of the formationssampled.

The invention contemplates an improved sample receiving projectile, foruse in conjunction with a side wall core sampler of the type described,which permits the sample to be discharged from the projectile in oneintact, un-

hard to those which are soft and friable, may be analyzed to determinequantitatively the nature of the fluids, whether gas, oil or water, withwhich they are saturated, as well as certain physical characteristics ofthe formation, such as its permeability and its porosity, which mayaffect the potential production of fluids from the formation.

One of the procedures followed in the search for peing a cylindricalhousing, usually about 6 feet long and about 4 inches in diameter, islowered in the drilled hole by means of a strong steel cable. Along oneedge, and perpendicular to the long axis of the instrument, a pluralityof sample receiving projectiles are fitted in line, one over the other.Usually there are about 30 of such projectiles per instrument. Theprojectiles each consist of a hollow cylinder having an open end andcapable of receiving a sample of the material of the side wall formationupon shooting the cylinder into the formation.

The projectiles are each shot into the side wall formation by detonatingan explosive charge placed in the instrument behind the projectile. Theexplosive charges are capable of being detonated electrically by remotecontrol.

The projectiles are attached to the housing of the instrument by meansof strong wires, so that after they have been fired they may beretrieved, with the core samples contained therein, upon raising theinstrument to the surface.

The design of the sample receiving projectiles above referred to, andthe dimensions thereof, may vary. A

altered piece. I

A novel feature of the invention is a split sleeve which forms an innerlining for the projectile and receives the sample as it is introducedinto the projectile. The sleeve is made of spring steel, and is capableof being expanded, due to its inherent resilience, upon removing thesleeve from the projectile with the sample contained therein, wherebythe sleeve is substantially disengaged from the a sample and the samplemay be recovered in one intact,

unaltered piece.

The invention will be readily understood by referring to the followingdescription and the accompanying drawing, in which:

Fi g. l is a diagrammatic elevational view of a side wall core samplerhaving incorporated therein a plurality of projectiles embodying theinvention, and showing the respective positions of the severalprojectiles as the sampler is lowered into a well bore, before any ofthe projectiles have been fired;

Fig; 2 is a fragmentary view, on an enlarged scale, of a portion of theapparatus illustrated in Fig. 1, showing the position of one of theprojectiles after it has been fired into the side wall of the Well bore;

Fig. 3 is a sectional view, taken on a median line, of one of theprojectiles;

Fig. 4 is a sectional view taken on the line 44 of Fig. 3; and v Fig. 5is a perspective view of an inner sleeve which is an important featureof the projectile shown in Figs. 3 and 4.

Referring to Fig. 1 of the drawing, a side wall core sampler having anelongated cylindrical housing 1 is shown positioned in a well bore 2 andsuspended from the surface by a steel cable 3. A plurality ofprojectiles embodying the invention, as hereinafter described, which aredesignated generally by the numeral 4, are each received in one of aplurality of longitudinally spaced openings 5 which are providedtherefor in the wall of the housing 1, and extend outwardly therefrom.The

When the side wall core is so tightly v projectiles 4 are each connectedto the housing 1 by a pair of wires 6, as hereinafter describdQwherebythe projectiles 4 may be retrieved after they have been fired.

Fig.2 shows the-position of -one of the -projectiles 4 after it has beenfired whereby it-isshot from the hous ing 1 byndetonationof anexplosive'charge. placed behind it, intheusualmanner, and lodgesin theside wall of the wellbore 2.

Referringto Figs. 3 to :5 of the drawing, each of the projectiles 4 hasatubular body 7,-which is threaded inter' nally at8, adjacent one endthereof. An annular groove 9 .is=formed inthe peripheral-surface of thebody 7 adja-- cent its opposite end. A plug--10,-which has a threadedportion -11 for engagement withthethreads 8, is received in one endofthe body 7. The plug -has a=pair of depressions "12 formed in the outerend-therefor for engagementby a wrench.

A sleeve 13, which is made of spring steel and issplit at 14, along oneside thereof, is-received within the body 7. Oneend of the sleeve-13abuts the adjacent endof the plug .10, and the opposite end of thesleeve 13 is flush with theadjacent end of the body 7. The sleeve 13 ischaracterized by its-resilience, whereby it must be compressed inorderto insert it in the body 7, and is expanded upon withdrawing ittherefrom.

An annular closure member 15, which has an inside diameter correspondingto the inside diameter of the sleeve 1-3 when compressed and an outsidediameter larger than the outside diameter of the body 7, has anexternally tapered outerend 16 and'is enlarged internally at 17,adjacent its opposite end, to forman internal shoulder 18.

One end of the body 7, with the sleeve 13 inserted therein, is receivedin'the internally enlarged portion 17 of theclosure member 15, and theadjacent ends of the body 7 and the sleeve 13 abut the internal shoulder18.

The closure member is detachably connected to the adjacent end of thebody 7 by an O ring 19, which is made of spring steel and is split at20. The O ring 19 is received partly in the annular groove 9 and partlyin an annular groove 21, which is formed-in the inner wall of'theclosure member 15 and is aligned with the groove 9. The O ring 19 ischaracterized by its resilience, whereby it is urged outwardly inengagement with the groove 21 The depth of the groove 9 is such that theO ring 19, when compressed, is capable of being disengaged from thegroove 21. I I V A plurality of circumferentially spaced openings 22 areformed in the body 7 adjacent the threaded end thereof, whichconstitutes the rearward end of the projectile 4 as it is fired, asshown in Fig. 2. A plurality of circumferentially spaced openings 23,which are aligned with the openings 22, are formed in the wall of thesleeve 13. Drilling fluid, with which the well bore 2 andthefinterior ofthe sleeve 13 may be filled at the time theprojectile 4 is fired, may bedisplaced from the sleeve 13-throughthe openings22 and-23 upon impact ofthe projectile 4 with the side wall of the well bore 2, whe'rebythematerial of the side wall is caused to enter the sleeve 13 through Thewires 6 are each connected at one end to one of the plugs 24,'and at itsopposite end to one oftwo threaded plugs 26 which are received inthreaded openings provided therefor in opposite sides of the housing 1.

In taking the sample, the sample passes through the opening in theclosure member 15 and is received within the sleeve 13. At thesurface,'the sleeve 13 is removed from the body 7 with the sample whichit contains. Upon removal'of the sleeve 13 from thebody 7, the'sleeve'13 springs out slightly, due to its inherentresilience, andexpands enough to release the pressure on the sample. With the pressurereleased, the sample may be removed from the sleeve13in one-intact,'unaltere'cl'piece:

The closure member 15 prevents damage to the sleeve 13 when theprojectile 4 strikes the side wall of the well bore 2. The O ring 19retains the closure member 15 in engagement with the body 7 as theinstrument is lowered in the well bore 2, but is capable of releasingthe closure member 15 from the body 7 if the closure member 15 shouldbecomecaught'in the'side wall after the projectile" 4 has been fired.The closure member 15 is expendable,

andmaybe left in theside'wall of'the' well 'bore2.

The invention may be'm'odified in various ways without'' tions from theside walls of well bores, a sample receiv ing' projectilecapable ofbeing shot from the instrument whereby it is'forced into an adjacentformation, the pro jectile'comprising anopen ended tubular body, aninner lining consisting of a split sleeve received in the body andcapable of receiving'a sample'of the material of the'"fo'i'- 'mation,upon firing the projectile, the sleeve being made of'spring steelandbeing capable of being expanded,"du'e to -its inherent resilience, uponremoving the sleeve'fror'n thebodywith'th'e' sample contained therein,whereby the? sleeve is substantially disengaged from the sample andthesample maybe recovered'in'one intact, unaltered pieceyan 'annularclosure member detachably connected toone end-of the body, the adjacentends of the' body and the"sleeve"being received in an internallyenlarged end portion'of the closure member, the body and the closure fmember having mutually aligned annular grooves formed inthe adjacentsurfacesthereof, and a split O r'ing received in'theannular grooves, the"0 ring being made of spring 5" steel and being capable ofbeing'expandedfdue to its inherent resilience, whereby it is disposedpartly in one" of the grooves'and partly in the other, the depth of thegroove formed in the body being such that the O ring, ,7 upon beingcompressed, may be disengaged from 'the 'f groove formed in the closuremember whereby the closure member may be detached from the body.

References Cited in the file of this patent UNITED STATES PATENTS2,055,506 Schlumberger Sept. 29, 1936 j 2,288,210 Schlumberger June 30,1942 2,600,125 Natland et a1. June'lO, 1952 2,678,804 Lebough May '18,1954 2,721,055 Madson et al Oct. 18, 1955 2,737,247 7 Baker etal Mar.6,1956

